Handbook of Electrical Engineering

(Romina) #1

  • 1 Estimation of Plant Electrical Load About the Author xxv

    • 1.1 Preliminary Single-Line Diagrams

    • 1.2 Load Schedules

      • 1.2.1 Worked example



    • 1.3 Determination of Power Supply Capacity

    • 1.4 Standby Capacity of Plain Cable Feeders and Transformer Feeders

    • 1.5 Rating of Generators in Relation to their Prime Movers

      • 1.5.1 Operation at low ambient temperatures

      • 1.5.2 Upgrading of prime movers



    • 1.6 Rating of Motors in Relation to their Driven Machines

    • 1.7 Development of Single-Line Diagrams

      • 1.7.1 The key single line diagram

      • 1.7.2 Individual switchboards and motor control centres



    • 1.8 Coordination with other Disciplines

      • 1.8.1 Process engineers

      • 1.8.2 Mechanical engineers

      • 1.8.3 Instrument engineers

      • 1.8.4 Communication and safety engineers

      • 1.8.5 Facilities and operations engineers

      • Reference





  • 2 Gas Turbine Driven Generators

    • 2.1 Classification of Gas Turbine Engines

      • 2.1.1 Aero-derivative gas turbines

      • 2.1.2 Light industrial gas turbines

      • 2.1.3 Heavy industrial gas turbines

      • 2.1.4 Single and two-shaft gas turbines

      • 2.1.5 Fuel for gas turbines



    • 2.2 Energy Obtained from a Gas Turbine

      • 2.2.1 Effect of an inefficient compressor and turbine

      • 2.2.2 Maximum work done on the generator

      • 2.2.3 Variation of specific heat viii

        • pressure drop 2.2.4 Effect of ducting pressure drop and combustion chamber



      • 2.2.5 Heat rate and fuel consumption



    • 2.3 Power Output from a Gas Turbine

      • 2.3.1 Mechanical and electrical power losses

      • 2.3.2 Factors to be considered at the design stage of a power plant



    • 2.4 Starting Methods for Gas Turbines

    • 2.5 Speed Governing of Gas Turbines

      • 2.5.1 Open-loop speed-torque characteristic

      • 2.5.2 Closed-loop speed-power characteristic

      • 2.5.3 Governing systems for gas turbines

      • 2.5.4 Load sharing between droop-governed gas turbines

      • 2.5.5 Load sharing controllers



    • 2.6 Mathematical Modelling of Gas Turbine Speed Governing Systems

      • 2.6.1 Modern practice

      • 2.6.2 Typical parameter values for speed governing systems

      • References

      • Further Reading





  • 3 Synchronous Generators and Motors

    • 3.1 Common Aspects Between Generators and Motors

    • 3.2 Simplified Theory of Operation of a Generator

      • 3.2.1 Steady state armature reaction

      • 3.2.2 Transient state armature reaction

      • 3.2.3 Sub-transient state armature reaction



    • 3.3 Phasor Diagram of Voltages and Currents

    • 3.4 The Derived Reactances

      • dimensions 3.4.1 Sensitivity ofxmd,xa,xfandxkdto changes in physical



    • 3.5 Active and Reactive Power Delivered from a Generator

      • 3.5.1 A general case

      • 3.5.2 The particular case of a salient pole generator

      • 3.5.3 A simpler case of a salient pole generator



    • 3.6 The Power Versus Angle Chart of a Salient Pole Generator

    • 3.7 Choice of Voltages for Generators

    • 3.8 Typical Parameters of Generators

    • 3.9 Construction Features of High Voltage Generators and Induction Motors

      • 3.9.1 Enclosure

      • 3.9.2 Reactances

      • 3.9.3 Stator windings

      • 3.9.4 Terminal boxes

      • 3.9.5 Cooling methods

      • 3.9.6 Bearings

      • References





  • 4 Automatic Voltage Regulation ix

    • 4.1 Modern Practice

      • 4.1.1 Measurement circuits

      • 4.1.2 Error sensing circuit

      • 4.1.3 Power amplifier

      • 4.1.4 Main exciter



    • 4.2 IEEE Standard AVR Models

      • 4.2.1 Worked example

      • 4.2.2 Worked example

      • 4.2.3 Determining of saturation constants

      • 4.2.4 Typical parameter values for AVR systems

      • Reference





  • 5 Induction Motors

    • 5.1 Principle of Operation of the Three-Phase Motor

    • 5.2 Essential Characteristics

      • 5.2.1 Motor torque versus speed characteristic

      • 5.2.2 Motor starting current versus speed characteristic

      • 5.2.3 Load torque versus speed characteristic

      • 5.2.4 Sensitivity of characteristics to changes in resistances and reactances

      • 5.2.5 Worked example

      • 5.2.6 Typical impedance data for two-pole and four-pole induction motors

      • 5.2.7 Representing the deep-bar effect by two parallel branches



    • 5.3 Construction of Induction Motors

    • 5.4 Derating Factors

    • 5.5 Matching the Motor Rating to the Driven Machine Rating

    • 5.6 Effect of the Supply Voltage on Ratings

    • 5.7 Effect of the System Fault Level

    • 5.8 Cable Volt-drop Considerations

    • 5.9 Critical Times for Motors

    • 5.10 Methods of Starting Induction Motors

      • 5.10.1 Star-delta method

      • 5.10.2 Korndorfer auto-transformer method

      • 5.10.3 Soft-start power electronics method

      • 5.10.4 Series reactor method

      • 5.10.5 Part winding method

      • References





  • 6 Transformers

    • 6.1 Operating Principles

    • 6.2 Efficiency of a Transformer

    • 6.3 Regulation of a Transformer

    • 6.4 Three-Phase Transformer Winding Arrangements

    • 6.5 Construction of Transformers

      • 6.5.1 Conservator and sealed type tanks



    • 6.6 Transformer Inrush Current x

      • References





  • 7 Switchgear and Motor Control Centres

    • 7.1 Terminology in Common Use

    • 7.2 Construction

      • 7.2.1 Main busbars

      • 7.2.2 Earthing busbars

      • 7.2.3 Incoming and busbar section switching device

      • 7.2.4 Forms of separation

      • 7.2.5 Ambient temperature derating factor

      • 7.2.6 Rated normal current

      • 7.2.7 Fault making peak current

      • 7.2.8 Fundamental AC part

      • 7.2.9 DC part

      • 7.2.10 Double frequency AC part

      • 7.2.11 Fault breaking current

      • 7.2.12 Fault withstand duty



    • 7.3 Switching Devices

      • 7.3.1 Outgoing switching device for switchgear

      • 7.3.2 Outgoing switching device for motor control centres



    • 7.4 Fuses for Motor Control Centre Outgoing Circuits

    • 7.5 Safety Interlocking Devices

    • 7.6 Control and Indication Devices

      • 7.6.1 Restarting and reaccelerating of motors

      • 7.6.2 Micro-computer based systems



    • 7.7 Moulded Case Circuit Breakers

      • 7.7.1 Comparison with fuses

      • 7.7.2 Operating characteristics

      • 7.7.3 Cut-off current versus prospective current

      • 7.7.4 i-squared-tcharacteristic

      • 7.7.5 Complete and partial coordination of cascaded circuit breakers

      • 7.7.6 Worked example for coordination of cascaded circuit breakers

      • 7.7.7 Cost and economics

      • References





  • 8Fuses

    • 8.1 General Comments

    • 8.2 Operation of a Fuse

    • 8.3 Influence of the Circuit X-to-R Ratio

    • 8.4 TheI^2 tCharacteristic

      • 8.4.1 Worked example

      • References





  • 9 Cables, Wires and Cable Installation Practices xi

    • 9.1 Electrically Conducting Materials used in the Construction of Cables

      • 9.1.1 Copper and aluminium

      • 9.1.2 Tin

      • 9.1.3 Phosphor bronze

      • 9.1.4 Galvanised steel

      • 9.1.5 Lead

      • Cables 9.2 Electrically Non-Conducting Materials used in the Construction of

      • 9.2.1 Definition of basic terminology



    • 9.3 Composition of Power and Control Cables

      • 9.3.1 Compositional notation

      • 9.3.2 Conductor

      • 9.3.3 Conductor semiconducting screen

      • 9.3.4 Insulation

      • 9.3.5 Insulation semiconductor screen

      • 9.3.6 Inner sheath

      • 9.3.7 Lead sheathing

      • 9.3.8 Armouring

      • 9.3.9 Outer sheath



    • 9.4 Current Ratings of Power Cables

      • 9.4.1 Continuous load current

      • 9.4.2 Continuous rated current of a cable

      • 9.4.3 Volt-drop within a cable

      • 9.4.4 Protection against overloading current



    • 9.5 Cables with Enhanced Performance

      • 9.5.1 Fire retardance

      • 9.5.2 Fire resistance

      • 9.5.3 Emission of toxic gases and smoke

      • 9.5.4 Application of fire retardant and fire resistant cables

      • Reference





  • 10 Hazardous Area Classification and the Selection of Equipment

    • 10.1 Historical Developments

    • 10.2 Present Situation

    • 10.3 Elements of Hazardous Area Classification

      • 10.3.1 Mixtures of gases, vapours and air



    • 10.4 Hazardous Area Zones

      • 10.4.1 Non-hazardous area

      • 10.4.2 Zone 2 hazardous area

      • 10.4.3 Zone 1 hazardous area

      • 10.4.4 Zone 0 hazardous area

      • 10.4.5 Adjacent hazardous zones



    • 10.5 Types of Protection for Hazardous Areas xii

      • 10.5.1 Type of protection ‘d’

      • 10.5.2 Type of protection ‘e’

      • 10.5.3 Type of protection ‘i’

      • 10.5.4 Type of protection ‘m’

      • 10.5.5 Type of protection ‘n’ and ‘n’

      • 10.5.6 Type of protection ‘o’

      • 10.5.7 Type of protection ‘p’

      • 10.5.8 Type of protection ‘q’

      • 10.5.9 Type of protection ‘s’

      • 10.5.10 Type of protection ‘de’



    • 10.6 Types of Protection for Ingress of Water and Solid Particles

      • 10.6.1 European practice

      • 10.6.2 American practice



    • 10.7 Certification of Hazardous Area Equipment

    • 10.8 Marking of Equipment Nameplates

      • References

      • Further Reading





  • 11 Fault Calculations and Stability Studies

    • 11.1 Introduction

    • 11.2 Constant Voltage Source – High Voltage

    • 11.3 Constant Voltage Source – Low Voltage

    • 11.4 Non-Constant Voltage Sources – All Voltage Levels

    • 11.5 Calculation of Fault Current due to Faults at the Terminals of a Generator

      • 11.5.1 Pre-fault or initial conditions

      • 11.5.2 Calculation of fault current – rms symmetrical values



    • 11.6 Calculate the Sub-Transient symmetrical RMS Fault Current Contributions

      • 11.6.1 Calculate the sub-transient peak fault current contributions



    • 11.7 Application of the Doubling Factor to Fault CurrentIfrms′′ found in 11.6

      • 11.7.1 Worked example

      • 11.7.2 Breaking duty current



    • 11.8 Computer Programs for Calculating Fault Currents

      • 11.8.1 Calculation of fault current – rms and peak asymmetrical values

      • 11.8.2 Simplest case

      • 11.8.3 The circuit x-to-r ratio is known

      • 11.8.4 Detailed generator data is available

      • 11.8.5 Motor contribution to fault currents



    • 11.9 The use of Reactors

      • 11.9.1 Worked example



    • 11.10 Some Comments on the Application of IEC60363 and IEC60909

    • 11.11 Stability Studies

      • 11.11.1 Steady state stability

      • 11.11.2 Transient stability

      • References xiii

      • Further Reading





  • 12 Protective Relay Coordination

    • 12.1 Introduction to Overcurrent Coordination

      • 12.1.1 Relay notation



    • 12.2 Generator Protection

      • 12.2.1 Main generators

      • 12.2.2 Overcurrent

      • 12.2.3 Differential stator current relay

      • 12.2.4 Field failure relay

      • 12.2.5 Reverse active power relay

      • 12.2.6 Negative phase sequence relay

      • 12.2.7 Stator earth fault relays

      • 12.2.8 Over terminal voltage

      • 12.2.9 Under terminal voltage

      • 12.2.10 Under- and overfrequency



    • 12.3 Emergency Diesel Generators

    • 12.4 Feeder Transformer Protection

      • 12.4.1 Overcurrent

      • 12.4.2 High-set or instantaneous current

      • 12.4.3 Characteristics of the upstream source



    • 12.5 Feeder Cable Protection

      • 12.5.1 Overcurrent protection

      • 12.5.2 Short-circuit protection

      • 12.5.3 Earth fault protection



    • 12.6 Busbar Protection in Switchboards

      • 12.6.1 Busbar zone protection

      • 12.6.2 Overcurrent protection

      • 12.6.3 Undervoltage protection



    • 12.7 High Voltage Induction Motor Protection

      • 12.7.1 Overloading or thermal image

      • 12.7.2 Instantaneous or high-set overcurrent

      • 12.7.3 Negative phase sequence

      • 12.7.4 Core balance earth fault

      • 12.7.5 Differential stator current

      • 12.7.6 Stalling current

      • 12.7.7 Limitation to the number of successive starts

      • 12.7.8 Undercurrent

      • 12.7.9 High winding temperature

      • 12.7.10 High bearing temperature

      • 12.7.11 Excessive vibration



    • 12.8 Low Voltage Induction Motor Protection

      • 12.8.1 Overloading or thermal image

      • 12.8.2 Instantaneous or high-set overcurrent

      • 12.8.3 Negative phase sequence xiv

      • 12.8.4 Core balance earth fault

      • 12.8.5 Stalling current

      • 12.8.6 Limitation to the number of successive starts



    • 12.9 Low Voltage Static Load Protection

      • 12.9.1 Time-delayed overcurrent

      • 12.9.2 Instantaneous or high-set overcurrent

      • 12.9.3 Core balance earth fault

      • Inverse Relays 12.10 Mathematical Equations for Representing Standard, Very and Extremely

      • References





  • 13 Earthing and Screening

    • 13.1 Purpose of Earthing

      • 13.1.1 Electric shock

      • 13.1.2 Damage to equipment

      • 13.1.3 Zero reference potential



    • 13.2 Site Locations

      • 13.2.1 Steel structures

      • 13.2.2 Land-based plants

      • 13.2.3 Concrete and brick-built structures



    • 13.3 Design of Earthing Systems

      • 13.3.1 High voltage systems

      • 13.3.2 Low voltage three-phase systems

      • 13.3.3 IEC types of earthing systems

      • 13.3.4 Earth loop impedance

      • 13.3.5 Earthing rods and grids



    • 13.4 Construction Details Relating to Earthing

      • 13.4.1 Frames, casings and cubicle steelwork

      • 13.4.2 Screwed and clearance hole entries

      • 13.4.3 Earthing only one end of a cable



    • 13.5 Screening and Earthing of Cables used in Electronic Circuits

      • 13.5.1 Capacitance and inductance mechanisms

      • 13.5.2 Screening against external interference

      • 13.5.3 Earthing of screens

      • 13.5.4 Screening of high frequencies

      • 13.5.5 Power earths, cubicle and clean earths

      • References





  • 14 Variable Speed Electrical Drivers

    • 14.1 Introduction

      • 14.1.1 Environment

      • 14.1.2 Power supply

      • 14.1.3 Economics



    • 14.2 Group 1 Methods

      • 14.2.1 Simple variable voltage supplies

      • 14.2.2 Pole-changing of the stator winding

      • 14.2.3 Pole amplitude modulated motors xv

      • 14.2.4 Wound rotor induction motors



    • 14.3 Group 2 Methods

      • 14.3.1 Variable voltage constant frequency supply

      • 14.3.2 Variable frequency variable voltage supply



    • 14.4 Variable Speed DC Motors

    • 14.5 Electrical Submersible Pumps

      • 14.5.1 Introduction

      • 14.5.2 Electrical submersible pump construction



    • 14.6 Control Systems for AC Motors

      • References





  • 15 Harmonic Voltages and Currents

    • 15.1 Introduction

    • 15.2 Rectifiers

      • 15.2.1 Diode bridges

      • 15.2.2 Thyristor bridges

      • 15.2.3 Power transistor bridges

      • 15.2.4 DC motors



    • 15.3 Harmonic Content of the Supply Side Currents

      • 15.3.1 Simplified waveform of a six-pulse bridge

      • 15.3.2 Simplified commutation delay

      • 15.3.3 Fourier coefficients of the line current waveform

      • 15.3.4 Simplified waveform of a 12-pulse bridge



    • 15.4 Inverters

      • 15.4.1 Basic method of operation

      • 15.4.2 Three-phase power inversion

      • 15.4.3 Induction motor fed from a voltage source inverter



    • 15.5 Filtering of Power Line Harmonics

    • 15.6 Protection, Alarms and Indication

      • References





  • 16 Computer Based Power Management Systems

    • 16.1 Introduction

    • 16.2 Typical Configurations

    • 16.3 Main Functions

      • 16.3.1 High-speed load shedding

      • 16.3.2 Load shedding priority table

      • 16.3.3 Low-speed load shedding

      • 16.3.4 Inhibiting the starting of large motors

      • 16.3.5 VDU display of one-line diagrams

      • 16.3.6 Active power sharing for generators

      • 16.3.7 Isochronous control of system frequency

      • 16.3.8 Reactive power sharing for generators

      • 16.3.9 Isochronous control of busbar voltage

      • 16.3.10 Condition monitoring of the gas turbines

      • 16.3.11 Scheduling the starting up and shutting down of the main generators

      • 16.3.12 Control of the reacceleration of motor loads xvi

      • 16.3.13 Auto-synchronising of the main generators

        • status reporting 16.3.14 Data logging, archiving, trending display, alarms, messages and







  • 17 Uninterruptible Power Supplies

    • 17.1 AC Uninterruptible Power Supplies

      • 17.1.1 The inverter

        • rated current 17.1.2 Coordination of the sub-circuit rated current with the inverter



      • 17.1.3 Earth fault leakage detection



    • 17.2 DC Uninterruptible Power Supplies

      • 17.2.1 UPS battery chargers

      • 17.2.2 Batteries



    • 17.3 Redundancy Configurations

      • References





  • 18 Miscellaneous Subjects

    • 18.1 Lighting Systems

      • 18.1.1 Types of lighting fittings

      • 18.1.2 Levels of illumination



    • 18.2 Navigation Aids

      • 18.2.1 Flashing marker lights

      • 18.2.2 White and red flashing lights

      • 18.2.3 Navigation buoys

      • 18.2.4 Identification panels

      • 18.2.5 Aircraft hazard lighting

      • 18.2.6 Helicopter landing facilities

      • 18.2.7 Radar

      • 18.2.8 Radio direction-finder

      • 18.2.9 Sonar devices



    • 18.3 Cathodic Protection

      • References





  • 19 Preparing Equipment Specifications

    • 19.1 The Purpose of Specifications

    • 19.2 A Typical Format for a Specification

      • 19.2.1 Introduction

      • 19.2.2 Scope of supply

      • 19.2.3 Service and environmental conditions

      • 19.2.4 Compliant international standards

      • 19.2.5 Definition of technical and non-technical terms

      • 19.2.6 Performance or functional requirements

      • 19.2.7 Design and construction requirements

      • 19.2.8 Inspection and testing

      • 19.2.9 Spare parts

      • 19.2.10 Documentation

      • 19.2.11 Appendices



    • as Applied to Synchronous Generators and Induction Motors 20 Summary of the Generalised Theory of Electrical Machines

    • 20.1 Introduction

    • 20.2 Synchronous Generator

      • 20.2.1 Basic mathematical transformations



    • 20.3 Some Notes on Induction Motors

      • 20.3.1 Derived reactances

      • 20.3.2 Application of three-phase short circuit

      • 20.3.3 Derived reactances and time constants for an induction motor

      • 20.3.4 Derivation of an equivalent circuit

      • 20.3.5 ‘Re-iteration or recapitulation’

        • induction motor 20.3.6 Contribution of three-phase short-circuit current from



      • References

      • Further Reading





  • Appendix A Abbreviations Commonly used in Electrical Documents

    • for Specifying Equipment Appendix B A List of Standards Often Used for Designing Electrical Systems and

    • B.1 International Electro-technical Commission (Europe)

    • B.2 Institute of Petroleum (UK)

    • B.3 International Standards Organisation (Worldwide)

    • B.4 British Standards Institution (UK)

    • B.5 American Petroleum Institute (USA)

    • B.6 Counseil International des Grands Reseaux Electriques (France)

    • B.7 Engineering Equipment and Materials Users Association (UK)

    • B.8 Electricity Council (UK)

    • B.9 Verband Deutscher Electrechniker (Germany)

    • B.10 Institute of Electronic and Electrical Engineers Inc. (USA)

    • B.11 Miscellaneous References from the UK

    • Devices for Power Systems Appendix C Numbering System for Protective Devices, Control and Indication

      • for Power System Circuits C.1 Application of Protective Relays, Control and Alarm Devices

      • C.1.1 Notes to sub-section C.1



    • C.2 Electrical Power System Device Numbers and Functions

    • Driven Generators Appendix D Under-Frequency and Over-Temperature Protection of Gas-Turbine



  • Appendix E List of Document Types to be Produced During a Project

    • E.1 Contractors Documents

      • E.1.1 Feasibility studies

      • E.1.2 Conceptual design

      • E.1.3 Detail design



    • E.2 Manufacturers Documents xviii

      • E.2.1 Feasibility studies

      • E.2.2 Conceptual design

      • E.2.3 Detail design





  • Appendix F Worked Example for Calculating the Performance of a Gas Turbine

    • F.1 The Requirements and Data Given

    • F.2 Basic Requirements

    • F.3 Detailed Requirements

    • F.4 Basic Solutions

    • F.5 Detailed Solutions

    • Containing an Induction Motor Appendix G Worked Example for the Calculation of Volt-drop in a Circuit

    • G.1 Introduction

    • Shock Hazard Potential Difference in a Rod and Grid Earthing System Appendix H Worked Example for the Calculation of Earthing Current and Electric

    • H.1 Worked Example



  • Appendix I Conversion Factors for the SI System of Units

    • I.1 Fundamental SI Units

    • I.2 Derived Non-electrical Units

    • I.3 Derived Electrical Units

    • I.4 Conversions

      • I.4.1 Length

      • I.4.2 Area

      • I.4.3 Volume

      • I.4.4 Mass and density

      • I.4.5 Velocity and acceleration



    • I.4.6 Force

      • I.4.7 Torque

      • I.4.8 Power

      • I.4.9 Energy and work

      • I.4.10 Pressure

      • I.4.11 Moment of inertia and momentum

      • I.4.12 Illumination

      • I.4.13 Electricity and magnetism

      • I.4.14 Miscellaneous quantities



    • I.5 International Standards Organisation (ISO) Conditions

    • I.6 Standard Temperature and Pressure (STP) Conditions

    • I.7 Regularly Used Constants

    • I.8 Regularly Used Prefixes

    • I.9 References



  • Index

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